Dust extinction map of the Galactic plane based on the VVV survey data

Artikel i vetenskaplig tidskrift, 2022

Dust extinction is one of the most reliable tracers of the gas distribution in the Milky Way. The near-infrared (NIR) Vista Variables in the Via Lactea (VVV) survey enables extinction mapping based on stellar photometry over a large area in the Galactic plane. We devise a novel extinction mapping approach, XPNICER, by bringing together VVV photometric catalogues, stellar parameter data from StarHorse catalogues, and previously published X percentile and PNICER extinction mapping techniques. We apply the approach to the VVV survey area, resulting in an extinction map that covers the Galactic disc between 295 degrees less than or similar to l less than or similar to 350 degrees and -2 degrees less than or similar to b less than or similar to 2 degrees, and the Galactic bulge between -10 degrees less than or similar to b less than or similar to 5 degrees. The map has 30 arcsec spatial resolution and it traces extinctions typically up to A(V) similar to 10-20 mag and maximally up to A(V) similar to 30 mag. We compare our map to previous dust-based maps, concluding that it provides a high-fidelity extinction-based map, especially in its ability to recover both the diffuse dust component of the Galaxy and moderately extincted giant molecular cloud regions. The map is especially useful as independent, extinction-based data on the Galactic dust distribution and applicable for a wide range of studies from individual molecular clouds to the studies of the Galactic stellar populations.